Ernie Ball 2721 Cobalt Regular Slinky Electric Strings

.010-.046 Electric Guitar Strings - Cobalt
Ernie Ball 2721 Cobalt Regular Slinky Electric Strings image 1
Ernie Ball 2721 Cobalt Regular Slinky Electric Strings image 1
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Ernie Ball 2721 Cobalt Regular Slinky Electric Strings
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Next-gen Guitar Strings

Ernie Ball Cobalt guitar strings are made of a new alloy formulation that gives you higher output, better sound, and longer life. Cobalt strings' special iron/cobalt blend attracts the magnets in your pickups better than any other alloy. When you string up with Ernie Ball Cobalts, you'll immediately notice the incredible comfort these strings offer - silky and pliable under your fretting fingers; your pick will seem to glide over the strings, letting you execute fast passages effortlessly. And when you plug in, you'll get increased power, beefy yet defined lows, improved midrange focus, harmonics, and sustain, and crisp highs. Try a set of Ernie Ball Cobalt strings - you're gonna love 'em!

Ernie Ball Cobalt Guitar Strings at a Glance:
  • Beta tested by the creme de la creme
  • Cobalt formula gives you higher output and better sound
  • Cobalts last longer
Beta tested by the creme de la creme

In the development of their Cobalt strings, Ernie Ball tapped select members of their star-studded artist roster - including Steve Morse, John Petrucci, Randy Jackson, Tony Levin, and Slash - to be beta testers for the new formulation. John Petrucci reported that the Cobalts sound "amazing," with "increased power, incredible clarity, and incredible sonic balance." He noted that the Cobalts seem "softer" under your fretting fingers (the term he used was "buttery"). Slash noted that - before being plugged in - the Cobalts "have an entirely different feel than normal strings." He goes on to characterize this sensation as "bouncy and pliable," and "a lot of fun for bending." When amplified, Slash commented that the Cobalts were just as bright as titanium strings, but more "guttural," with more "growl to them."

Cobalt formula gives you higher output and better sound

A half century ago, Ernie Ball practically invented "rock" guitar strings. And now, with Cobalt, they've re-invented them. After exhaustive testing of over 350 alloy combinations, the company ended up with an optimal formula that - as compared with conventional strings - gives you higher output, beefier lows with increased definition, improved midrange focus, shimmering harmonics and more robust sustain. You get a brighter sound without inducing harshness by turning up the treble on your amp.

Cobalts last longer

Ernie Ball Cobalt guitar strings last longer, retaining their brightness long after other strings have given up the ghost. Steve Morse reported having a set on one of his guitars "for several weeks," and with daily use - "sweaty hands" and all - the Cobalts "still sound bright... They just don't have that dead sound," he says. So, with higher output, better sound, and the monetary benefits of not having to change strings so often, Cobalts have it all over traditional alloy formulations. Check out a set of Ernie Ball Cobalt strings - you'll love 'em!

Ernie Ball Cobalt Guitar Strings Features:
  • Punchier, higher output strings
  • Beefier lows, with increased definition and growl
  • Increased midrange focus, harmonics, and sustain
  • Longer-lasting than conventional strings
  • .010, .013, .017, .026, .036, .046
  • Made in USA
Try the strings the pros ar raving about: Ernie Ball Cobalt guitar strings

Tech Specs

Guitar Type Electric
Number of Sets 1
Coated No
Gauges .010, .013, .017, .026, .036, .046
Core Material Steel
Winding Material Iron/cobalt alloy
Winding Type Round
Manufacturer Part Number P02721

Customer Reviews

Based on 23 reviews
Write your review

Superb Strings period

I was reluctant but a friend gave me a set. Ive used the D'addarios for years. Just happened to break a string and his gift set was all I had. Tied`em on and wow. They were full of tone, and slightly louder I suppose. But Tone for days. So, I started using them and have been ever since. I have tried some of the coated strings and they`re just too bright and jangle. These strings are awesome. But I would reluctantly state that these strings are maybe not for beginners nor those who don`t play their guitar regularly, because they are strong. But if you are a daily player you`ll not notice the difference. They also last longer. My normal time frame, when gigging steadily, on a set of strings before using these was about once every week or two, now, I tie on a new set about once every 3-4 weeks.
Music background: 20+ year pro


First of all I've been a regular slinky fan for 40 years! I've tried a few different brands over the years. And the only ones that came close to my ears were the GHS Boomers. But they didn't cut the mustard... That was 20 years ago. And only because our lead player used them. He was wrong!!! Reg Slinky's are the best I've ever used! Until now... These "Cobalts" are better! They hold their intonation even when new!!! And they really do make your axe sound better!!! Point in case... I bought a Gibson "SGJ14" in December and thought it was weak. And stated so in my review. You can read it for yourself! And at the time I meant every word of it!!! I thought the pups sucked! But after a couple weeks, I broke one of the strings Gibson put on it from the factory. So I decided to put the "Cobalts" I bought during the holiday season. What a difference!!! I couldn't believe the tone I was getting just by changing my strings!!! It was truly amazing. I can't wait to replace the strings on my other guitars! Give them a try Mikey, you'll like 'em!
Music background: 40+ years playin' Blues, Rock, Country, and Jazz.

thought it was just hype

I don't buy into the next big thing most of the time,but i thought i would try these strings.I noticed a big difference right away.I bought the 10-46 set but to me they play and feel like a 9 set.for some reason the tension seems lighter more rubbery in a sense.I had my setup the same as far as guitar amps and so on,and there is a volume difference.A person just learning to play might not notice it,but its like there is more of what was there before,if that makes sense.I haven't put down my guitar for about 4 hours now,everything seems to be easier to play.....a bit more smooth....
Music background: Music teacher

Best string out there

I bought these strings to try out on my Les Paul will never buy anything else they sound so nice clear you can hear ever note I'll I have to say is people that don't like them are to cheap to pay the price of the strings or they are playing on guitars that are not set up properly if your guitar is not set up right you will never hear the beauty these strings give these string are for pro's if your a beginner you will think a ten dollar fleamarket amp sounds great Lmao

Ernie Ball Slinky Cobalt (Hawaii)

I've tried many different strings and wasn't to much a gimmick biter.. Everyone claims to have the best strings and rightfully they should feel that way cause it's their own product.. I have two small string endorsements that I've had for awhile until I got signed by Ernie Ball-music man a month or so ago.. I've used their super slinky for years and lets face it "there's nothing better then a great set of fresh strings on your instruments"! Being that this is my comment and review on these Cobalts I want you to know in no way am I bring partial or bias but giving you a true fact! Ready? Here it comes.. "Ernie Ball Cobalt strings are the best strings I've ever used in my entire life"! I've been a solidified professional full-time musician for 17 years and counting and I'm on stage a minimum of twice a week to 6-7 days a week.. I've literally tried them all or atleast I feel I have.. These strings are a pleasure to use and feel so seductive and light but still holds beautiful tone,sustain is amazing and the output seems to have more gain in it.. Idk what else I could say but this " best strings on the market" hands down! Aloha
Music background: Artist,musician,producer,recording engineer and Ernie Ball- Music ManArtist
See also: Electric Strings, Ernie Ball, Ernie Ball Electric Guitar Strings